Featured Research

Saving The Cypress: Replanting Unsuccessful Without Dual Cultivation With Lavender Or Mycorrhizal Fungi

Date:

January 21, 2007

Source:

Institut de Recherche Pour le Développement

Summary:

In the forests of the High Atlas, reforestation with cypress is one of the priorities of the Moroccan government's environmental management strategy. A research team involving Cadi Ayyad University of Marrakech, the High Atlas Regional Forestry Directorate and IRD researchers studied an ecological strategy for restoring vegetation in this area. The investigations focused on interactions between cypress trees, the pioneer plants -- lavender and thyme -- and mycorrhizal soil fungi with which these different species associate.

Share This

Morocco possesses a rich and varied flora, owing partly to its great diversity of relief and landscapes. However, advancing erosion and processes of desertification, combined with the development of human activities, are damaging this biodiversity. One of the representative species of this flora, the cypress Cupressus atlantica, is experiencing year by year a decrease in its biomass production and the surface areas it occupies.

Related Articles

This species contributes to efforts to control erosion and degradation of forest soils. But it is highly sought after by local communities particularly for the quality of its wood. In addition, the young shoots are subjected to overgrazing (by sheep) which hinders the species' natural regeneration. Replanting operations have been undertaken, but have proved largely unsuccessful, with nearly 70 % of the young saplings planted dying after the first year.

To counter the threat hanging over this species, a research programme was set up in 2003, jointly between the Cadi Ayyad University of Marrakech, the High Atlas Regional Forestry Directorate and scientists from IRD research unit UR 040 (1). The IRD researchers proposed an original ecological approach, founded on the study of interactions between the cypress, the shrubby plants--lavender and thyme--associated with them and the soil microflora, in order to define new practices for cypress replanting schemes in the Moroccan Atlas.

Cypress develops symbiotically with soil micro-fungi, arbuscular mycorrhizal fungi (2). This association yields mutual benefits, the plant providing sugars for the fungi which in return helps provide the tree's supply of water and mineral salts, mainly of nitrogen and phosphorus. In controlled mycorrhization glasshouse experiments, the researchers inoculated strains of these fungi, sampled from the study zones in the Moroccan High Atlas, into young nursery plants. There resulted a distinct improvement in the development of these young cypress with inoculated mycorrhizal fungi, which had a higher level of minerals in their leaves (21 % more phosphorus, in particular). Other experiments, conducted in the field, confirmed this result: the fungi favour better nutrition for the young cypress which enables them to build up greater resistance to transplantation-linked hydric stress for when they are adult. Although it is effective, this plant-by-plant inoculation technique remains cumbersome and costly, which limits its large-scale use.

In the cypress stands of the Moroccan High Atlas, several species of lavender and thyme are associated with the trees. These pioneer species, which form sparse clumps of vegetation, are the first to colonize the stony eroded soils of these arid and semi-arid ecosystems. Soil analyses revealed that these species generate islands of fertility, resource islands, rich in nitrogen and phosphorus, as well as in mycorrhizal fungi with which these plants also live in symbiosis. However, what role do they play in the development of young planted cypress saplings?

Lavender and cypress grown together and inoculated with mycorrhizal fungi under glass showed significantly higher growth than when they were cultivated and developed separately. Moreover, the concentration of propagules (3) appeared greater around the lavender roots than around those of cypress and, even more so, than around bare soil (244.5, 179.7 and 7.82 for 100 g of dry soil respectively). Lavender therefore favours the proliferation of mycorrhizal fungi and of their mycelium in the soil. As it reproduces, this "nurse" plant multiplies the number of resource islands generated, which eventually increases the fertility of the whole of the terrain involved. It therefore creates conditions that encourage growth of the planted cypress, stabilizing the soil as it does so by its roots.

Increased understanding of the process of natural regeneration of cypress trees has allowed the application of a new method of replanting of this species in the Moroccan High Atlas. In the sites that must be re-wooded, bands of lavender were planted in strips of earth built up perpendicularly to the slope so as to retain water. The cypress saplings were planted the following year. The first results confirm the beneficial role lavender has on these young plantations: their mortality after one year proves to be very low and soil erosion remains limited. Research investigations were also conducted on other associations of species, such as cork oak and cysts, or again thujas and lavender. The latter are the subject of a trial conducted by the Rabat Regional Forestry Directorate in areas undergoing reforestation in the North of Morocco.

(1) These investigations were conducted by the IRD, in conjunction with and at the request of Moroccan partners, jointly with the 'Laboratoire Ecologie and Environnement' of the Semlalia Faculty of Sciences (Université Cadi Ayyad). The IRD team (UR 040, led by R. Duponnois) belongs to the 'Laboratoire des symbioses tropicales and méditerranéennes (LSTM)', UMR 113, which also involves CIRAD, INRA, Agro-Montpellier and the University of Montpellier II. This work takes up the thesis of Lahcen Ouahmane, produced in the team of Prof. Mohamed Hafidi in conjunction with R. Duponnois and which is due to be judged in February 2007 at Marrakech.

(2) Arbuscules are fungal structures that symbiotic fungi form inside the root cells of most cultivated plants and many forest tree species. They are the site of nutritional exchanges between the two partners in the symbiosis. The fungi moreover develop a vast network of mycelial threads in the ground, which acts as a vital interface between the soil and the plant.

(3) In the fungi, these are the groups, of cells that initiate the development of the tubular mycelial threads (a process of asexual reproduction).

More From ScienceDaily

More Plants & Animals News

Featured Research

Mar. 3, 2015 — While studying a ground-nesting bird population near El Reno, Okla., a research team found that stress during a severe weather outbreak of May 31, 2013, had manifested itself into malformations in ... full story

Mar. 3, 2015 — The 3-D printing scene, a growing favorite of do-it-yourselfers, has spread to the study of plasma physics. With a series of experiments, researchers have found that 3-D printers can be an important ... full story

Mar. 3, 2015 — Most people consume more salt than they need and therefore have a higher risk of heart disease and stroke, which are the two leading causes of death worldwide. But a new study reveals that dietary ... full story

Mar. 3, 2015 — By examining the forces that the segments of mosquito legs generate against a water surface, researchers have unraveled the mechanical logic that allows the mosquitoes to walk on water, which may ... full story

Mar. 3, 2015 — Pediatric otolaryngologists and surgeons are concerned with parents getting the wrong message regarding the safety/desirability of letting babies and young children eat peanuts to prevent them from ... full story

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — Similar to humans and animals, plants possess an innate immune system that protects them from invading pathogens. Molecular structures that only occur in pathogens enable their recognition and ... full story

Mar. 3, 2015 — For almost a century, scientists have been puzzled by a process that is crucial to much of the life in Earth's oceans: Why does calcium carbonate, the tough material of seashells and corals, ... full story

Mar. 3, 2015 — To simulate chimp behavior, scientists created a computer model based on equations normally used to describe the movement of atoms and molecules in a confined space. An interdisciplinary research ... full story

Featured Videos

Rare Goblin Shark Found in Australia

AFP (Mar. 3, 2015) — A goblin shark, a rare sea creature described as an &apos;alien of the deep&apos; is found off Australia and delivered to the Australian Museum in Sydney. Duration: 01:25
Video provided by AFP

Zookeepers Copy Animal Poses In Hilarious Viral Photos

Buzz60 (Mar. 2, 2015) — Zookeepers at the Symbio Wildlife Park in Helensburgh, Australia decided to take some of their favorite animal photos and recreate them by posing just like the animals. Jen Markham (@jenmarkham) has the story.
Video provided by Buzz60

Related Stories

May 20, 2014 — A key mechanism in the symbiosis between fungi and trees has been uncovered by researchers. During this mutually beneficial interaction, the fungus takes control of its host plant by injecting a ... full story

Jan. 8, 2014 — Microscopic fungi that live in plants' roots play a major role in the storage and release of carbon from the soil into the atmosphere, according to new research. The role of these fungi is ... full story

Oct. 23, 2012 — Researchers have found beneficial effects of the Pseudomonas fluorescens bacterium for the colonization of the black truffles on the pine roots. These results can be promising to enhance the ... full story

Oct. 1, 2012 — Cheating. Conflict. Competition. It may sound like a soap opera but this is the complex life of the despised ragweed plant. And in the highly competitive fight for nutrients, researchers have found ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.